Aluminium and calcium deposits have been demonstrated in brain tissue of patients with Alzheimer's disease, progressive dialysis dementia, amyotrophic lateral sclerosis and parkinsonian-dementia by x-ray microprobe analysis. However, in these previous studies, aluminum and calcium were not imaged and the distributions of these elements were not well characterized. This work applied the computer controlled, electron beam x-ray microanalysis system to image aluminum and calcium in the hippocampus of patients with these diseases. Aluminum images obtained from such cases clearly show high concentrations of aluminum in neurofibrillary tangle-bearing neurons (NFT), a pathological cell type associated with these conditions. Calcium images show calcium has the same distribution as aluminum and is concentrated in the NFT neurons. The graphical information produced by this work clearly demonstrates that the aluminum and calcium are sequestered in NFT neurons, the distributions of the elements overlap and provide further evidence correlating high concentrations of aluminum and calcium with specific pathological structures in these diseases.